Hypodermic syringe



7, 1962 KRUEGER 3,048,172

HYPODERMIC SYRINGE Filed May 20, 1960 INVENTOR.

NICHOLAS KRUEGER ATTORNEY United States Patent 3,048,172 HYPODERMICSYRINGE Nicholas Krueger, Woodridge, N.J., assignor to East RutherfordSyringes, Inc., Rutherford, N.J., a corporation of New Jersey Filed May20, 1960, Ser. No. 30,588 8 Claims. (Cl. 128-218) This invention relatesto hypodermic syringes, and more particularly, concerns the needlemounting or lock thereon. Y

Hypodermic syringes conventionally comprise a glass barrel whichterminates at its forward end in a headed bored tip. Needle mountingmeans, in the form of a metal sleeve is force fitted on the barrel tip;the mounting means being provided at its forward end with the usualthreaded portion for locking engagement with the hub of a needle whichis to be associated with the syringe barrel.

While the force fit of the metal sleeve on the barrel tip appears toprovide a firm connection between tip and sleeve; in many instances theconnection is somewhat insecure and separation of the sleeve from thetip is not unusual, thereby materially shortening the normal life of thesyringe.

Furthermore, with substantially 1 increased sterilizing temperatures;autoclave sterilization being performed now with dry steam at about 350F., there is noted an increased tendency for separation of the sleevefrom the barrel tip.

Accordingly, an object of this invention is to provide an improvedneedle mounting construction for syringe barrels which is free ofseparation of the parts despite extreme conditions of usage.

Another object of this invention is to provide an improved needlemounting construction which is economical to manufacture and isassembled with the syringe barrel in an expeditious manner.

A further object of this invention is to provide a needle mounting ofthe character described, wherein the wall structure embracing thesyringe barrel tip is of a character which allows for a gripping actionwhich prevents separation of the parts despite the application oftension or torsional forces, or the development of stresses due toexposure of the syringe to elevated temperatures.

Other objects of this invention will in part be obvious and in parthereinafter pointed out.

In the drawing, FIG. 1 is a partial view in longitudinal section of thetip end of a syringe barrel; FIG. 2 is \a longitudinal section of aneedle mounting embodying the invention; FIG. 3 is a longitudinalsectional view showing the mounting of FIG. 2 assembled on the tip ofthe barrel shown in FIG. 1; and FIG. 4 is a side ,view, with parts insection, of a syringe barrel assembled with a needle mounting, showing amodification of the invention.

Referring in detail to the drawing, and particularly to FIG. 1, 10designates the tip end portion of a hypodermic syringe bar-rel, usuallyformed of glass, and adapted to be associated with a plunger, not shown,in a manner known in the art. The barrel 10 has extending from theforward end thereof the usual headed tip 11 joined to the barrel by ashort neck portion 12, providing tip 11 with a rear shoulder 13.

The tip 11, which is bored axially as at 14 for communication with theinterior of barrel 11, may have a very slight taper towards the forwardend thereof and may have its surface 15 ground to insure uniformity ofthe outer surface, all in a manner known in the art.

As shown in FIG. 2, there is provided a needle mounting or lock 16, forsecure attachment on barrel tip 11. Mounting 16 comprises a metal sleeveportion 17, a transverse partition 18 at the forward end of sleeveportion 17,

an axially disposed tapered portion 19 extending forwardly of partition18 and an internally threaded collar 20 concentrically related totapered portion 19. It is understood, that the hub of a needle, notshown, is fitted into collar 20 and twisted to a locking position, withportion 19 received in the hub bore. Partition 18 may be formed on itsinner face with a circular recess for receiving a gasket '21 to provideleak-proof connection when needle mounting 16 is assembled with barreltip 11.

The metal sleeve portion 17 of needle mounting 16 includes a wallportion 22 of uniform thickness, which extends over the major portion ofthe longitudinal extent of the sleeve portion. Extending rearwardly ofwall portion 22 is a second wall portion 23 of reduced thickness, saidwall portion 23 forming a minor portion of the longitudinal extent ofsleeve portion 17.

The needle mounting 16 is assembled with barrel 10 in a conventionalmanner, by a force fitting operation wherein barrel tip 11 istelescopically received in sleeve portion 17, with the end 24 of the tip11 abutting the inner surface of partition 18 of the needle mounting 16,gasket 21 being compressed therebetween to make a leak-proof connection.The tapered portion 19 of the mounting 16 is axially bored forconnecting tip bore 14 with the bore of the needle, not shown.

The needle mounting 16 is formed of brass or other suitable alloy ormetal, which can be readily machined.

It has been found, that when sleeve 17 of the mounting includes the rearwall portion 23 of a thickness less than the thickness of the forwardwall portion 22, the grip of the sleeve on barrel tip 11 issubstantially increased, particularly, when the rear edge 25 of wallportion 23 projects slightly beyond shoulder 13 on barrel tip 11.

Thus, upon testing a needle mounting embodying the invention, as mountedon a syringe barrel, it was found that the mounting resisted theapplication of positive torsional forces and remained secured to thetip, whereas the same forces applied to a conventional needle mounttingresulted in the mounting being twisted off the barrel tip. Similarly,when a plurality of each type of needle mounting associated with glasssyringe barrels were autoclaved at about 350 F., most of theconventional mountings had separated from their barrels, while none ofthe novel mountings had separated from their associatcd barrels.

The thickness of sleeve wall portion 23 may be about /2 the thickness ofwall portion 22. Thus for a wall thickness of .025 for portion 22; wallportion 23 may have a thickness of .013". However, the thickness of wallportion 23 may range from about .008 to about .015".

In another embodiment of the invention, shown in FIG. 4, the needlemounting 16 may be positively secured to barrel tip 11, after telescopicassembly of the parts, by spinning the rear wall portion 23 of sleeve 17over shoulder 13 of'tip 11. The reduced thickness of the wall portion 23facilitates the spinning operation and avoids undue strain on the glasstip 11, particularly at the juncture of neck 12 and tip .11. Thus, thewall portion 22 of normal thickness is well adapted to withstand thestresses incident to attachment of the needle, not shown to need-1emounting 16, while the wall portion 23 of reduced thickness is adaptedto allow for a spinning or crimping operation about the shoulder 13 ofthe glass tip 11 without breakage of the tip.

As various changes might be made in the embodiments of the inventionherein shown without departing from the spirit thereof, it is understoodthat all matter herein disclosed shall be deemed to be illustrative andnot limiting except as set forth in the appended claims.

Having thus disclosed my invention, I claim as new and desire to protectby Letters Patent:

1. In a syringe, a syringe barrel, an integral tip exsore, 17.2

tending from one end of said barrel, said tip being bored to provide apassage communicating with the interior of said barrel, needle mountingmeans on said tip, said needle mounting means comprising a tubular metalsleeve telescopically mounted on said tip, said sleeve comprising aforwardly extending cylindrical wall portion of uniform thickness and acylindrical skirt portion of a uniform thickness less than the thicknessof said forwardly extending wall portion extending rear-wardly from saidforwardly extending wall portion.

2. In a syringe, a glass syringe barrel having a forwardly extendingintegral bored tip, a metal sleeve on said tip and projecting forwardlythereof, said sleeve having successive, longitudinally disposed wallportions of different uniform thickness, the wall portion of lesseruniform thickness throughout the longitudinal extent thereof beingdisposed about and tightly gripping the rear portion of said tip.

3. A spring as in claim 2 wherein the last mentioned wall portion has athickness of about /2 the thickness of the wall portion disposed aboutthe forward portion of said tip.

4. In a syringe, a glass syringe barrel having a forwardly extendingintegral bored tip, a needle mounting on said tip, said needle mountingcomprising a metal sleeve having one longitudinally extending wallportion of a uniform thickness which is a fraction of the thickness ofanother longitudinally extending wall portion thereof, both of said wallportions being disposed about and tightly gripping said tip.

5. In a syringe, a glass syringe barrel having a forwardly extendingbored, headed tip, a needle mounting on said tip, said needle mountingcomprising a metal sleeve having a rearwardly extending wall portion ofreduced uniform thickness, said wall portion being turned inwardly intoengagement with rear edge portions of said headed tip.

6. In a hypodermic syringe, a glass barrel having a bored tip and a neckportion extending rearwardly from said tip with an annular shoulder atthe juncture of said tip and neck portion, a needle mounting metalsleeve on said tip, said sleeve having a forwardly extending majorlongitudinal portion thereof of one uniform wall thickness and arearwardly extending minor longitudinal portion thereof of a uniformwall thickness about 4, to about /2 of said wall thickness.

7. A syringe as in claim 6 wherein the rear edge of the last mentionedsleeve portion extends rearwardly beyond the shoulder at the juncture ofsaid tip and neck portion.

8. A syringe as in claim 6 wherein the last mentioned sleeve portion isturned radially inward into contact with the shoulder at the juncture ofsaid tip and neck portion.

References Cited in the file of this patent UNITED STATES PATENTS1,998,982 Dickinson Apr. 23, 1935 2,755,801 Morando July 24, 19562,799,271 Sciurba July 16, 1957 2,811,155 Dunnican Oct. 29, 1957

